This invention relates to palletizing apparatus for palletizing units of goods, such as cartons, cases, stacks of papers, and the like.
The basic principles of palletizing are well known and are generally discussed in my U.S. Pat. No. 4,704,060, herein incorporated by reference in its entirety. As far as is known, though, conventional palletizers are generally limited to receiving goods from only one line (e.g. a production line) at a time, and can deliver layers of the goods received to only one location. While multiple streams of product have been combined ahead of the palletizer, as in U.S. Pat. No. 3,836,018 Dawson, multiple product streams have not been combined in, or otherwise concurrently fed into, a palletizer.
Accordingly, the efficiency of the layer transfer plate may not be optimized as it waits for formation of a layer as an output from a relatively slower production line. One option is to sequentially feed two or more different products along the same conveyor in an effort to more efficiently utilize the transfer plate. This provides opportunity for unwanted mixing of the different materials in that part of the processing operation which is common to being used by both products, and so this option is sometimes not preferred.
While it may be desirable to feed a plurality of production lines into and through a single palletizer, and wherein the production lines potentially produce different products, it is also desirable to minimize the amount of equipment that is commonly traversed by the different products, in order to reduce the potential for unintentional intermingling of the products.
To the extent the palletizing apparatus has the capacity to handle the incoming volume, it is desirable to use one palletizer to concurrently process the output of a plurality of material handling process lines, such as conveyors. This reduces the number of palletizers needed as well as reducing the floor space requirement, labor and maintenance costs, and the like.
Dawson '018 teaches sequential movement of partial pallet loads of units of material to the layer receiving locus. But such repeated moving of significant weights of material in order to bring the proper pallet load into alignment with the in-coming layer requires substantial load bearing equipment, and locomotion equipment, to effect movement of the plurality of partial loads, as well as substantial energy expended through such locomotion equipment to effect such movement.
In light of the above deficiencies in the art, it is one object of this invention to provide palletizers having two or more layer forming stations such that a plurality of layers of material (at least 2 layers) can be formed, namely constructed, simultaneously.
It is a particular object to provide a palletizer wherein the layer forming stations are arranged such that the transfer plate can be positioned at one location to pick up a layer from one of a selection of layer forming stations.
It is another object to provide a palletizer wherein the layer forming stations are spaced vertically with respect to each other thereby minimizing the floor space requirement of the palletizer.
It is still another object to provide a transfer plate, and carriage therefore, which are adapted to delivering layers of material to a plurality of load forming stations.
Still another object is to provide apparatus and method for combining partial layers of units of different materials to make a mixed layer, and to place such a mixed layer on a pallet.
A further object is to place a plurality of layers on a load, and wherein the materials in one such layer are different from the materials in another such layer.
Yet another object is to minimize the linear travel path of the transfer plate, thereby increasing its efficiency, by accomplishing vertical movement relative to the load forming station, by vertically moving the respective load forming station.
Still another object is to provide apparatus and methods to form layers of units of material on the in-feed conveyor by sequentially feeding rows of units of material across the in-feed conveyor and advancing the rows against a stop and against each other.